A builder wants to make a room soundproof and a new home the builder should use materials that

have high sound insulation properties such as:

1. Mass-loaded vinyl: A dense material that can be installed between walls to block sound transmission.

2. Soundproof drywall: Thicker and denser than regular drywall, it can help reduce noise transfer between rooms.

3. Acoustic panels: These sound-absorbing panels can be installed on walls or ceilings to reduce echoes and reverberation.

4. Green glue: A sound-dampening compound that can be sandwiched between layers of drywall to improve sound insulation.

5. Fiberglass insulation: Installing fiberglass insulation in the walls can help reduce noise transmission.

6. Sealing gaps and cracks: Ensuring that all gaps and cracks are sealed properly can help prevent sound leakage.

7. Double-glazed windows: Installing double-glazed windows with air pockets can help reduce noise from outside.

8. Soundproof doors: Using solid-core doors with weatherstripping can help block sound transmission between rooms.

By using these materials and techniques, the builder can create a soundproof room in the new home.